U.S. patent number 7,276,208 [Application Number 10/439,457] was granted by the patent office on 2007-10-02 for sample carrier having sample tube blocking member.
This patent grant is currently assigned to Gen-Probe Incorporated. Invention is credited to Gerard J. Sevigny, Mark A. Talmer, Gus G. Tseo, Matthew W. Webb.
United States Patent |
7,276,208 |
Sevigny , et al. |
October 2, 2007 |
Sample carrier having sample tube blocking member
Abstract
A sample carrier comprising a lower support wall, a base joined
to or in fixed proximity to a bottom end of the lower support wall,
and sample tube receiving areas in fixed proximity to the lower
support wall for receiving and holding a plurality of sample tubes
in substantially vertical orientations. The sample carrier further
comprising a blocking wall joined to a top end of the support wall
which extends laterally over portions of sample tubes held by the
sample carrier, thereby limiting vertical movement of the sample
tubes during automated sampling procedures. The contents of sample
tubes held by the sample carrier can be accessed by a robotic
pipetting device. Additionally, a drip shield comprising a cover
plate, a pair of through-holes for accessing sample tubes held by a
the sample carrier, and a depending runner for maintaining the
sample carrier on a sample carousel.
Inventors: |
Sevigny; Gerard J. (Nashua,
NH), Talmer; Mark A. (West Ford, MA), Webb; Matthew
W. (Del Mar, CA), Tseo; Gus G. (San Diego, CA) |
Assignee: |
Gen-Probe Incorporated (San
Diego, CA)
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Family
ID: |
29553539 |
Appl.
No.: |
10/439,457 |
Filed: |
May 16, 2003 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20030215365 A1 |
Nov 20, 2003 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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60443458 |
Jan 29, 2003 |
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60381551 |
May 17, 2002 |
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Current U.S.
Class: |
422/562;
211/74 |
Current CPC
Class: |
B01L
9/06 (20130101); G01N 35/025 (20130101); G01N
35/10 (20130101); B01L 3/50825 (20130101); B01L
2200/023 (20130101); B01L 2200/025 (20130101); B01L
2200/0615 (20130101); B01L 2200/141 (20130101); B01L
2300/021 (20130101); B01L 2300/041 (20130101); G01N
35/1011 (20130101); G01N 2035/0448 (20130101); G01N
2035/0451 (20130101); G01N 2035/0465 (20130101) |
Current International
Class: |
B01L
9/00 (20060101) |
Field of
Search: |
;422/62-66,99,102,104
;436/43,47-49 ;211/74 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0 100 663 |
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Feb 1984 |
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EP |
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0219802 |
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Apr 1987 |
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EP |
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0919281 |
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Jun 1999 |
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EP |
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0 965 385 |
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Dec 1999 |
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EP |
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0965385 |
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Dec 1999 |
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EP |
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1-161154 |
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Jun 1989 |
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JP |
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WO93/01739 |
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Feb 1993 |
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WO |
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Primary Examiner: Warden; Jill
Assistant Examiner: Handy; Dwayne K.
Attorney, Agent or Firm: Cappellari; Charles B.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application
No. 60/381,551, filed May 17, 2002, and U.S. Provisional
Application No. 60/443,458, filed Jan. 29, 2003, each of which
applications is hereby incorporated by reference herein.
Claims
We claim:
1. A sample carrier for use in holding and containing a plurality
of sample tubes for access by a fluid transfer device, the sample
carrier comprising: a lower support wall; a base joined to a bottom
end of the lower support wall; a plurality of sample tube receiving
areas adjacent the lower support wall for receiving and holding a
plurality of sample tubes in substantially vertical orientations;
and a sample tube blocking member that is provided to and
registered with the lower support wall opposite the base, wherein
the sample tube blocking member comprises a blocking wall that
extends laterally over only a portion of each of the sample tube
receiving areas.
2. The sample carrier of claim 1, wherein said sample carrier
further comprises one or more springs disposed within each of the
sample tube receiving areas for holding a corresponding sample tube
therein.
3. The sample carrier of claim 2, wherein each of the sample tube
receiving areas is defined by: a pair of fixed partitions, each
partition having a generally perpendicular or radial orientation
relative to the lower support wall; and one or more fixed retaining
walls having an opposed orientation relative to the lower support
wall.
4. The sample carrier of claim 3, wherein each partition separating
adjacent sample tube receiving areas and a pair of retaining walls
are joined to form a Y-shaped divider.
5. The sample carrier of claim 4, wherein the partitions which are
adjacent to only one sample tube receiving area and their
associated retaining walls form a pair of end walls.
6. The sample carrier of claim 3, wherein the one or more springs
comprise a leaf spring fixed by and extending outward relative to
the lower support wall and into one of the sample tube receiving
areas, wherein the leaf spring is configured and arranged to bias a
sample tube against the one or more retaining walls associated with
the corresponding sample tube receiving area.
7. The sample carrier of claim 6, wherein the leaf spring extends
outward through a slot formed in the lower support wall.
8. The sample carrier of claim 1, wherein each sample tube
receiving area comprises a slot formed in the base which is
configured to receive a sample tube therein.
9. The sample carrier of claim 8, wherein an opening extends
through an outer surface of the base adjacent the slot to permit
viewing of machine readable information affixed to an outer
surfaces of a sample tubes held by the slot.
10. The sample carrier of claim 1, wherein the sample tube blocking
member further comprises an upper support wall depending from the
blocking wall, and wherein the upper support wall is provided to
the lower support wall.
11. The sample carrier of claim 10, wherein the lower support wall
and the upper support wall comprise mated first and second
registration elements, respectively, for registering the sample
tube blocking member with the lower support wall.
12. The sample carrier of claim 11, wherein the first registration
elements comprise a pair of pins extending upward from a top
surface of the lower support wall, and wherein the second
registration elements comprise a pair of corresponding
through-holes in the upper support wall for receiving the pins
therethrough.
13. The sample carrier of claim 1, wherein the sample carrier
includes a plurality of sample tube receiving areas adjacent
opposite sides of the lower support wall.
14. The sample carrier of claim 13, wherein the sample carrier has
an arcuate shape.
15. A sample carrier for use in holding and containing a plurality
of sample tubes for access by a fluid transfer device, the sample
carrier comprising: a lower support wall; a base joined to a bottom
end of the lower support wall; a plurality of sample tube receiving
areas adjacent the lower support wall for receiving and holding a
plurality of sample tubes in substantially vertical orientations; a
transverse wall joined to an upper portion of the lower support
wall and having a plurality of spaced-apart openings, wherein each
opening is dimensioned to receive a sample tube therethrough, and
wherein the openings are aligned with the sample tube receiving
areas to maintain sample tubes held by the sample carrier in
substantially vertical orientations; and a sample tube blocking
member that is provided to and registered with a top end of the
transverse wall, and wherein the sample tube blocking member
comprises a blocking wall that extends laterally over only a
portion of each of the sample tube receiving areas.
16. The sample carrier of claim 15, wherein the sample tube
blocking member comprises an upper support wall depending from the
blocking wall and in touching contact with the top end of the
transverse wall.
17. The sample carrier of claim 15, wherein said sample carrier
further comprises one or more springs disposed within each of the
sample tube receiving areas for holding a corresponding sample tube
therein.
18. The sample carrier of claim 17, wherein each of the sample tube
receiving areas is defined by: a pair of fixed partitions, each
partition having a generally perpendicular or radial orientation
relative to the lower support wall; and one or more fixed retaining
walls having an opposed orientation relative to the lower support
wall.
19. The sample carrier of claim 18, wherein each partition
separating adjacent sample tube receiving areas and a pair of
retaining walls are joined to form a Y-shaped divider.
20. The sample carrier of claim 19, wherein the partitions which
are adjacent to only one sample tube receiving area and their
associated retaining walls form a pair of end walls.
21. The sample carrier of claim 18, wherein the one or more springs
comprise a leaf spring fixed by and extending outward relative to
the lower support wall and into one of the sample tube receiving
areas, wherein the leaf spring is configured and arranged to bias a
sample tube against the one or more retaining walls associated with
the corresponding sample tube receiving area.
22. The sample carrier of claim 21, wherein the leaf spring extends
outward through a slot formed in the lower support wall.
23. The sample carrier of claim 15, wherein: the lower support wall
comprises upper and lower portions; and the sample tube receiving
areas comprise a laterally extending wall positioned between and
joined to the upper and lower portions of the lower support wall,
wherein the laterally extending wall comprises a plurality of
spaced-apart openings substantially axially aligned with the
openings in the transverse wall, each opening in the laterally
extending wall being sized to receive a sample tube therethrough,
and wherein a set of finger springs depends from a bottom surface
of the laterally extending wall about the periphery of each
opening, each set of finger springs being configured and arranged
to hold a sample tube within the corresponding opening.
24. The sample carrier of claim 23, wherein the lower support wall
and the laterally extending wall form an integral piece.
25. The sample carrier of claim 23, wherein each set of finger
springs includes four finger springs.
26. The sample carrier of claim 23, wherein each finger spring
includes a distal node to facilitate removal of the sample tubes
from the sample tube holding receiving areas.
27. The sample carrier of claim 15, wherein the transverse wall and
the sampled tube blocking member comprise mated first and second
registration elements, respectively, for registering the sample
tube blocking member with the transverse wall.
28. The sample carrier of claim 27, wherein the first registration
elements comprise a pair pins extending upward from a top surface
of the transverse wall, and wherein the second registration
elements comprise a pair of corresponding through-holes in the
sample tube blocking member for receiving the pins
therethrough.
29. The sample carrier of claim 15, wherein a top surface of the
transverse wall is chamfered about the periphery of each
opening.
30. The sample carrier of claim 15 further comprising one or more
sample tubes held by the sample tube receiving areas, wherein a cap
component associated with each sample tube is at least partially
contained within the corresponding opening between top and bottom
surfaces of the transverse wall.
31. The sample carrier of claim 30, wherein each cap includes a
seal capable of being penetrated by a plastic pipette tip..
32. The sample carrier of claim 30, wherein the longitudinal axis
of the cap component associated with each sample tube is no more
than about 0.125 inches from the longitudinal axis of the
corresponding opening in the transverse wall.
33. The sample carrier of claim 15, wherein the sample carrier
includes a plurality of sample tube receiving areas adjacent
opposite sides of the lower support wall.
34. The sample carrier of claim 33, wherein the sample carrier has
an arcuate shape.
35. The sample carrier of claim 1 further comprising one or more
sample tubes held by the sample tube receiving areas, wherein the
blocking wall extends over only a portion of each of the sample
tubes held by the sample tube receiving areas, thereby limiting
vertical movement of the sample tubes held by the sample carrier
without obstructing access to the contents of the sample tubes by a
fluid transfer device.
36. The sample carrier of claim 3 further comprising one or more
sample tubes held by the sample tube receiving areas, wherein the
blocking wall extends over only a portion of each of the sample
tubes held by the sample tube receiving areas, thereby limiting
vertical movement of the sample tubes held by the sample carrier
without obstructing access to the contents of the sample tubes by a
fluid transfer device.
37. The sample carrier of claim 8 further comprising one or more
sample tubes held by the sample tube receiving areas, wherein the
blocking wall extends over only a portion of each of the sample
tubes held by the sample tube receiving areas, thereby limiting
vertical movement of the sample tubes held by the sample carrier
with out obstructing access to the contents of the sample tubes by
a fluid transfer device.
38. The sampler carrier of claim 15 further comprising one or more
sample tubes held by the sample tube receiving areas, wherein the
blocking wall extends over only a portion of each of the sample
tubes held by the sample tube receiving areas, thereby limiting
vertical movement of the sample tubes held by the sample carrier
without obstructing access to the contents of the sample tubes by a
fluid transfer device.
39. The sample carrier of claim 18 further comprising one or more
sample tubes held by the sample tube receiving areas, wherein the
blocking wall extends over only a portion of each of the sample
tubes held by the sample tube receiving areas, thereby limiting
vertical movement of the sample tubes held by the sample carrier
without obstructing access to the contents of the sample tubes by a
fluid transfer device.
40. The sample carrier of claim 21 further comprising one or more
sample tubes held by the sample tube receiving areas, whererin the
blocking wall extends over only a portion of each of the sample
tubes held by the sample tube receiving areas, thereby limiting
vertical movement of the sample tubes held by the sample carrier
without obstructing access to the contents of the sample tubes by a
fluid transfer device.
41. The sample carrier of claim 23 further comprising one or more
sample tubes held by the sample tube receiving areas, wherein the
blocking wall extends over only a portion of each of the sample
tubes held by the sample tube receiving areas, thereby limiting
vertical movement of the sample tubes held by the sample carrier
witout obstructing access to the contents of the sample tubes by a
fluid transfer device.
Description
FIELD OF THE INVENTION
The present invention relates to a sample carrier for holding and
containing a plurality of sample tubes. The sample carrier of the
present invention is especially suited for use with an automated
sampling system and sample tubes having penetrable caps. The
present invention further relates to a drip shield for protecting
against cross-contamination between sample tubes and for
substantially limiting vertical movement of sample carriers
positioned on conveying means during an automated sample
transfer.
INCORPORATION BY REFERENCE
All references referred to herein are hereby incorporated by
reference in their entirety. The incorporation of these references,
standing alone, should not be construed as an assertion or
admission by the inventors that any portion of the contents of all
of these references, or any particular reference, is considered to
be essential material for satisfying any national or regional
statutory disclosure requirement for patent applications.
Notwithstanding, the inventors reserve the right to rely upon any
of such references, where appropriate, for providing material
deemed essential to the claimed invention by an examining authority
or court. No reference referred to herein is admitted to be prior
art to the claimed invention.
BACKGROUND OF THE INVENTION
Procedures for determining the presence or absence of specific
organisms or viruses in a test sample commonly rely upon nucleic
acid-based probe testing. To increase the sensitivity of these
tests, an amplification step is often included to increase the
number of potential nucleic acid target sequences present in the
test sample. There are many procedures for amplifying nucleic acids
which are well known in the art, including, but not limited to, the
polymerase chain reaction (PCR), (see, e.g., Mullis, "Process for
Amplifying, Detecting, and/or Cloning Nucleic Acid Sequences," U.S.
Pat. No. 4,683,195), transcription-mediated amplification (TMA),
(see, e.g., Kacian et al., "Nucleic Acid Sequence Amplification
Methods," U.S. Pat. No. 5,399,491), ligase chain reaction (LCR),
(see, e.g., Birkenmeyer, "Amplification of Target Nucleic Acids
Using Gap Filling Ligase Chain Reaction," U.S. Pat. No. 5,427,930),
strand displacement amplification (SDA), (see, e.g., Walker,
"Strand Displacement Amplification," U.S. Pat. No. 5,455,166), and
loop-mediated isothermal amplification (see, e.g., Notomi et al.,
"Process for Synthesizing Nucleic Acid," U.S. Pat. No. 6,410,278).
A review of several amplification procedures currently in use,
including PCR and TMA, is provided in HELEN H. LEE ET AL., NUCLEIC
ACID AMPLIFICATION TECHNOLOGIES (1997).
A concern with amplification is the possibility of
cross-contamination, since transferring even a minute amount of
target-containing sample to a target-negative sample could lead to
the production of billions of target sequences in the "negative"
sample. As a consequence, a test may indicate a positive result for
a sample actually lacking nucleic acid from an organism or virus of
interest. The source of a contaminating sample transfer may be an
aerosol or bubbles released from a sample tube when a cap component
of the sample tube is removed or penetrated by a practitioner or
instrument. To minimize such sources of contamination, penetrable
caps having filtering means were recently introduced and are
disclosed by Anderson et al., "Collection Device and Method for
Removing a Fluid Substance from the Same," U.S. Patent Application
Publication No. US 2001-0041336 A1, and Kacian et al., "Penetrable
Cap," U.S. Patent Application Publication No. US 2002-0127147
A1.
Components of penetrable caps generally exert a retention force
against fluid transfer devices (e.g., pipette tips) as they are
being withdrawn from corresponding sample tubes. See, e.g., Ammann
et al., "Automated Process for Isolating and Amplifying a Target
Nucleic Acid Sequence," U.S. Pat. No. 6,335,166 (an instrument for
performing amplification assays on test samples which includes a
robotic pipettor for obtaining test sample from a sample tube is
disclosed). The retention force may be attributable to, for
example, the sealing material of the cap and/or filtering means
included within the cap. If the retention force is too great, a
sample tube may be drawn out a sample carrier holding the sample
tube by an exiting pipettor. In a more extreme case, the retention
force of the cap and the sample tube holding force of the sample
carrier are each great enough that the sample carrier is lifted
vertically as the fluid transfer device is being withdrawn from the
sample tube.
Conventional sample carriers commonly rely upon springs to
immobilize distal ends of sample tubes, biasing the sample tubes
against one or more opposing surfaces of the sample carriers. And
more recently, a sample carrier has been described which further
includes a top wall portion having a plurality of openings which
are configured and arranged so that penetrable caps affixed to the
vessel components of sample tubes are positioned snugly within the
openings when the sample tubes are held by the sample carrier,
thereby centering the sample tubes by restricting lateral movement
of the corresponding caps within the openings. See Dale et al.,
"Sample Carrier and Drip Shield for Use Therewith," U.S. Patent
Application Publication No. US 2003-0017084 A1. What these sample
carriers lack, however, is a mechanism for ensuring that sample
tubes remain in the sample carriers during automated sampling
procedures when the retention force of a cap is greater than the
holding force of the sample carrier on an associated vessel
component. As a consequence, there is a risk that penetrable caps
which exert too great a retention force against fluid transfer
devices will be withdrawn, along with their associated vessel
components, from sample carriers during automated sampling
procedures. Thus, a need exists for a sample carrier capable of
containing sample tubes having penetrable caps in their allotted
positions on the sample carrier during automated sampling
procedures.
SUMMARY OF THE INVENTION
The present invention solves the sample tube containment problem
associated with known sample carriers by providing a sample carrier
comprising a lower support wall, a base joined to or in fixed
proximity to a bottom end of the lower support wall, and sample
tube holding means in fixed proximity to the lower support wall for
receiving and holding a plurality of sample tubes in substantially
vertical orientations. The sample carrier further comprises a
sample tube blocking member comprising a blocking wall joined
directly or indirectly to a top end of the lower support wall,
wherein the sample tube holding means is configured beneath the
blocking wall of the sample tube blocking member such that the
blocking wall extends over a portion of each sample tube held by
the sample tube holding means, thereby limiting vertical movement
of the sample tubes held by the sample carrier without obstructing
access to the contents of the sample tubes by a robotic pipetting
device. As used herein, the term "indirectly" means that there is
intervening structure between and connecting the elements being
joined.
In a preferred embodiment of the present invention, the sample
carrier further comprises a transverse wall joined to the lower
support wall, preferably an upper portion of the lower support
wall. The sample tube blocking member of this embodiment further
comprises an upper support wall depending from the blocking wall
which is directly or indirectly joined to the transverse wall. The
transverse wall includes a plurality of spaced-apart openings,
where each opening is dimensioned to receive a sample tube
therethrough, and where the openings are aligned with the sample
tube holding means to maintain sample tubes held by the sample
carrier in substantially vertical orientations. The openings are
preferably circular in geometry, and the size of the openings may
be the same or different to accommodate sample tubes having caps of
equal or different diameters. Preferably, a top surface of the
transverse wall is chamfered about the periphery of each of opening
to facilitate insertion of the sample tubes into the sample tube
holding means.
The openings of the transverse wall are preferably positioned so
that at least a portion of the sample tube caps are contained
within the openings between top and bottom surfaces of the
transverse wall when the sample tubes are fully inserted into the
sample tube holding means. Ideally, when portions of the caps are
contained within the openings, the longitudinal axis of each cap
should be no more than about 0.125 inches (3.18 mm) from the
longitudinal axis of the corresponding opening and more preferably
no more than about 0.1 inches (2.54 mm) from the longitudinal axis
of the opening. Centering the caps prior to piercing them with a
robotic pipetting device can aid in limiting the force required to
penetrate the caps and, accordingly, can provide for more accurate
pipetting.
In one embodiment of the present invention, the sample tube holding
means comprises a series of sample tube receiving areas, each
sample tube receiving area being defined by: (i) a pair of fixed
partitions having a generally perpendicular or radial orientation
relative to the lower support wall; (ii) one or more fixed
retaining walls having an opposed orientation relative to the lower
support wall; and (iii) one or more springs disposed within each of
the sample tube receiving areas for holding a corresponding sample
tube therein. In a preferred embodiment, the one or more springs
employed to hold each sample tube in a corresponding sample tube
receiving area comprises a leaf spring which is fixed by and
extends outward relative to the support wall and into the sample
tube receiving area. Preferably, the leaf spring extends outward
through a slot formed in the lower support wall. The leaf spring is
configured and arranged to bias the sample tube against the one or
more retaining walls associated with the corresponding sample tube
receiving area. The leaf spring may be chemically treated or
physically altered to increase the coefficient of friction between
the leaf spring and outer surfaces of the sample tubes. Regardless
of the type of springs used, the springs preferably have a holding
force of at least about 0.5 pounds force (2.22 N). The holding
force should be sufficient to maintain sample tubes held by a
sample carrier in a substantially vertical orientation and to
prevent rotation of the sample tubes. As used herein, the phrase
"holding force" refers to the force a spring exerts against a
sample tube in a sample tube holding area, and the term "spring" is
to be given its ordinary meaning, referring to an elastic device
which substantially regains its original shape after being
compressed.
In another embodiment of the present invention, the lower support
wall is comprised of upper and lower portions and the sample tube
holding means comprises a laterally extending wall positioned
between and joined to upper and lower portions of the lower support
wall. (The upper and lower portions of the lower support wall and
the laterally extending wall may be separate components joined by
any suitable attachment means (e.g., screws) or they may be
integrally molded.) The laterally extending wall includes a
plurality of spaced-apart openings, where each of the openings is
dimensioned to receive a sample tube therethrough. The openings in
the laterally extending wall are substantially axially aligned with
the openings in the transverse wall. The base may include upwardly
extending partitions having a generally perpendicular or radial
orientation relative to the lower support wall which are positioned
below and between adjacent openings in the laterally extending
wall.
In a preferred embodiment, a set of finger springs may be provided
to the laterally extending wall, where each set of finger springs
depends from a bottom surface of the laterally extending wall about
the periphery of one of the openings. Each set of finger springs in
this embodiment is configured and arranged to hold a sample tube in
a generally vertical orientation within the corresponding sample
tube receiving area. A set of finger springs is preferably made up
of four finger springs depending inwardly toward the longitudinal
axis of the associated opening. A node having a curved end-surface
at the distal end of each finger spring is preferred to facilitate
removal of sample tubes after use.
In yet another embodiment of the present invention, the sample tube
holding means comprises a series of slots formed in the base, where
each slot is configured to receive a sample tube in a substantially
vertical orientation. In a preferred embodiment, a vertical opening
extending through an outer surface of the base adjacent each
opening is provided to permit viewing of machine readable
information (e.g., scannable bar code) affixed to an outer surface
of a sample tube contained within a corresponding slot.
In still another embodiment of the present invention, the sample
tube blocking member and the lower support wall or the transverse
wall may be may be releasably joined to each other by means of
mated first and second registration elements. In a preferred
embodiment, the first registration elements consist of a pair of
metal pins extending upward from a top surface of the lower support
wall or the transverse wall, and the second registration elements
consist of a pair of corresponding through-holes in the sample tube
blocking member for receiving the pins therethrough. The pins may
be adapted to include helical threads which extend above a top
surface of the sample tube blocking member for receiving mated nuts
for fixing the sample tube blocking member to the lower support
wall or to the transverse wall. Because the sample carrier is
preferably used in conjunction with a drip shield, such as the one
described infra, the exposed portions of the pins are preferably
contained entirely within the sample tube blocking member after
joining the sample tube blocking member to the lower support wall
or the transverse wall. Other releasable attachment means
contemplated by the present invention include, by way of example
only, clips, Velcro.RTM. or a snap-on arrangement.
In a further embodiment of the present invention, the partitions
separating adjacent sample tube receiving areas extend outward from
the lower support wall and upward from the base. In this
embodiment, the retaining walls, which have an opposed orientation
relative to the lower support wall, likewise extend upward from the
base. By "an opposed orientation" is meant that the retaining walls
have an orientation relative to the lower support wall other than
radial or perpendicular. For certain embodiments, the retaining
walls function to hold the sample tubes in the sample tube
receiving areas against the force of the springs, while for other
embodiments the retaining walls may simply aid in guiding sample
tubes into the sample tube receiving areas. Although it is not a
requirement that the partitions and retaining walls be joined to
each other, the partitions and pairs of associated retaining walls
are joined to each other in a preferred embodiment to form Y-shaped
dividers. With the Y-shaped dividers, the partitions need not
extend outward from the lower support wall.
Partitions at the ends of the sample carrier form a pair of end
walls. (The end walls are also referred to as "partitions" herein
to simplify the definition of a sample tube receiving area, even
though end walls are not ordinarily understood to be partitions.)
The end walls may serve as a surface for providing machine readable
information (e.g., scannable bar code) about the contents of the
sample tubes being carried by the sample carrier and/or about the
number and types of assays to be performed on the contents of the
sample tubes.
In yet a further embodiment of the present invention, the outer
surface of the lower support wall includes a plurality of machine
readable labels, each label being affixed to the lower support wall
above the sample tube holding means and below the transverse wall
or the sample tube blocking member. One such label is preferably
positioned above each sample tube receiving area of the preferred
sample carrier. The labels may include scannable bar codes or other
machine readable information which can be used to indicate whether
particular sample tubes are present in or absent from the sample
tube holding means.
In still a further embodiment of the present invention, the sample
tube holding means is capable of receiving and holding sample tubes
on both sides of the lower support wall. In this embodiment, the
blocking wall of the sample tube blocking member extends laterally
away from both sides of the lower support wall. The blocking wall
extends over only a portion of each sample tube on each side of the
lower support wall, thereby permitting unobstructed access to the
contents of the sample tubes by a robotic pipetting device.
The sample carrier of the present invention may have a rectilinear
or arcuate shape, although an arcuate shape is preferred. The
sample carrier is preferably has an arcuate shape for use on an
automated sample carousel.
In another embodiment of the present invention, a drip shield is
provided for use in an automated sampling system to protect the
contents of sample tubes held by sample carriers from fluid
contamination, especially hanging droplets which may be dislodged
from a robotic pipetting device during an automated sampling
procedure. By "automated sampling system" is meant a system for
holding a sample tube in a substantially vertical orientation and
conveying the sample tube by automated means to a location within
an apparatus where the contents of the sample tube may be accessed
by a robotic pipetting device in order to effect a transfer of at
least a portion of the contents to another location within the
apparatus. The drip shield of the present invention is preferably
constructed of a substantially non-conductive material and includes
a cover plate which may have an arcuate shape conforming to the
arcuate shape of the preferred sample carrier.
The cover plate of the drip shield includes one or more
through-holes, where each through-hole is configured and arranged
to provide non-interfering, vertical passage of an aligned pipette
tip therethrough. The through-holes are sized to permit access to
the contents of only one sample tube at a time, where the sample
tubes being accessed are present in a sample carrier positioned
beneath the cover plate. In a preferred embodiment, the diameter of
each through-hole is the same as or smaller than the smallest
diameter of any sample tube held by the sample carrier to minimize
opportunities for contaminating the sample carrier and its
contents. A top surface of the cover plate may be chamfered or,
alternatively, include a rim about the periphery of each
through-hole. A chamfered through-hole could aid in redirecting a
misaligned pipette tip through the through-hole, whereas a rimmed
through-hole would provide a further barrier to fluid contamination
of sample tubes. Because the sample carrier used in the preferred
automated sampling system includes two sets of sample tube
receiving areas on opposite sides of the lower support wall, the
drip shield includes at least two through-holes in the cover plate
which are configured and arranged to provide access to sample tubes
on opposite sides of the support wall.
Depending from a bottom surface of the cover plate is at least one
runner, an inner runner, which is configured and arranged to limit
vertical movement of a sample carrier positioned beneath the drip
shield. In the preferred embodiment, the drip shield further
includes two outer runners depending from the bottom surface of the
cover plate which are spaced-apart from the inner runner so that
inner side walls of the outer runners and both side walls of the
inner runner extend over sample tubes held by the sample carrier.
This arrangement of runners will block vertical movement of a
sample tube withdrawn from the sample tube holding means should the
sample tube blocking member fail in its function.
In the preferred drip shield, the inner runner has a flat bottom
surface which is substantially longitudinally or arcuately centered
on the bottom surface of the cover plate. The ends of the inner
runner may be tapered so that a sample carrier which is not fully
seated in a sample carrier receiving well of a sample carousel may
be progressively forced back into the corresponding sample carrier
receiving well. The inner runner is preferably positioned so that
the drip shield and the sample carrier are not in touching contact
prior to accessing the sample tubes. The distance between the
bottom surface of the inner runner and a top surface of the sample
tube blocking member of a sample carrier conveyed thereunder is
preferably no more than about 0.125 inches (3.12 mm).
In yet another embodiment of the present invention, an automated
sampling system is provided which includes one or more of the
above-described sample carriers having sample tube holding means
for receiving sample tubes on both sides of the lower support wall,
a sample carrier conveying means, and the above-described drip
shield which is located above and in fixed relationship to sample
carriers being transported thereunder.
These and other features, aspects, and advantages of the present
invention will become apparent to those skilled in the art after
considering the following detailed description, appended claims and
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of a preferred sample
carrier according to the present invention.
FIG. 2 is an exploded perspective view of another sample carrier
according to the present invention.
FIG. 3 is an exploded front view of the sample carrier of FIG.
1.
FIG. 4 is a perspective view of a spring cage of the sample carrier
of FIG. 1.
FIG. 5 is a front view of the spring cage of FIG. 4.
FIG. 6 is a front view of the sample carrier of FIG. 1 with two
sample tubes inserted into sample tube receiving areas thereof.
FIG. 7 is a top plan view of the sample carrier of FIG. 1 without a
sample tube blocking member, and where a transverse wall and an
upper portion of a lower support wall of the sample carrier are
integrated.
FIG. 8 is a top plan view of the sample carrier of FIG. 1 without
the sample tube blocking member.
FIG. 9 is a top plan view of the sample carrier of FIG. 1 with four
sample tubes inserted into sample tube receiving areas thereof.
FIG. 10 is a bottom view of the sample tube blocking member of the
sample carrier of FIG. 1.
FIG. 11 is a section end view of the sample carrier of FIG. 9,
taken along the 11--11 line thereof.
FIG. 12 is a bottom view of the sample carrier of FIG. 1.
FIG. 13 is an enlarged partial bottom view of the sample carrier of
FIG. 12 showing two sets of guide rails for inserting spring cages
of FIG. 4 into the sample carrier.
FIG. 14 is an end view of the sample carrier of FIG. 1 with an
identification plate attached thereto.
FIG. 15 is an exploded perspective view of another sample carrier
according to the present invention with two sample tubes inserted
into sample tube receiving areas.
FIG. 16 is a top plan view of the sample carrier of FIG. 15 without
the sample tube blocking member, and where the transverse wall and
the upper portion of the lower support wall are integrated.
FIG. 17 is a section end view of the sample carrier of FIG. 15,
taken along the 17--17 line thereof, and two sample tubes inserted
into sample tube receiving areas.
FIG. 18 is an enlarged partial perspective bottom view of the
laterally extending wall of FIG. 15.
FIG. 19 is a top view of another sample carrier according to the
present invention without the sample tube blocking member.
FIG. 20 is a front view of the sample carrier of FIG. 19 with the
sample tube blocking member.
FIG. 21 shows the sample carrier of FIG. 1 positioned on a sample
carousel and holding a single sample tube.
FIG. 22 is a perspective top view of a drip shield for use in an
automated sampling system according to the present invention.
FIG. 23 is a perspective bottom view of the drip shield of FIG.
22.
FIG. 24 is a section end view of the drip shield of FIG. 22, taken
along the 24--24 line thereof.
FIG. 25 is a section end view of an alternative drip shield for use
in an automated sampling system according to the present
invention.
FIG. 26 is a section end view of the sample carrier of FIG. 1
carried under the drip shield of FIG. 22 by the sample carousel of
FIG. 21.
The sample carriers illustrated in the attached drawings include a
number of redundant features. Where it would be clear to those
skilled in the art from reviewing the drawings and reading the
following description what features are being shown, the inventors
have attempted to avoid including an excessive number of reference
numbers by providing reference numbers for only a representative
number of similar features depicted therein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the present invention may be embodied in a variety of forms,
the following description and accompanying drawings are merely
intended to disclose some of those forms as specific examples of
the present invention. Accordingly, the present invention is not
intended to be limited to the forms or embodiments so described and
illustrated. Instead, the full scope of the present invention is
set forth in the appended claims.
With reference to the figures, preferred sample carriers 10 of the
present invention are shown alone or in combination with a drip
shield 200 for protecting against cross-contamination between
sample tubes 300 carried by the sample carriers and for limiting
vertical movement of the sample carriers when sample is being
removed from any of the sample tubes. (Reference herein to a
"sample carrier 10" is a general reference of to any of the
illustrated sample carriers 10A-D.) Sample carriers 10 of the
present invention are preferably used in combination with sample
tubes 300 having sealed caps 310 which can be penetrated by
standard pipette tips for use with positive displacement pipettes.
To ensure proper alignment for penetrating these caps 310 and
pipetting sample, the sample carriers 10 of the present invention
substantially immobilize the sample tubes 300 they carry, thereby
limiting both vertical and lateral movement of the sample tubes
during sampling procedures. The sample tubes 300 used with the
sample carriers 10 of the present invention may be transport tubes
provided with sample collection kits which are used to receive and
store samples for shipping and future analysis, including analysis
with nucleic acid-based assays or immunoassays diagnostic for a
particular pathogenic organism or virus. Such samples may include,
for example, blood, urine, saliva, sputum, mucous or other bodily
secretion, pus, amniotic fluid, cerebrospinal fluid, seminal fluid,
tissue specimens, stool, environmental samples, food products,
chemicals, powders, particles or granules. The sample tubes 300 may
be of any shape or composition, provided vessel components 320 of
the sample tubes are shaped to receive and retain the material of
interest (e.g., animal, environmental, industrial, food or water
samples). The vessel component 320 includes a closed end and an
open end adapted for fixing the cap 310 thereto (e.g., mated
helical threads). Preferred sample tubes are disclosed by Anderson
et al., U.S. Patent Application Publication No. US 2001-0041336 A1,
and Kacian et al., U.S. Patent Application Publication No. US
2002-0127147 A1. It is generally important that the composition of
the sample tube 300 be essentially inert relative to the sample so
that it does not significantly interfere with the performance or
results of an assay.
As illustrated in FIG. 1, a particularly preferred sample carrier
10A according to the present invention includes a transverse wall
20, a base 30, a lower support wall 40 which joins the top wall and
the base in fixed relationship, and a plurality of springs 50,
where each spring is disposed within a sample tube receiving area
60. (Reference herein to a "sample tube receiving area 60" is a
general reference of to any of the illustrated sample tube
receiving areas 60A-C.) This preferred sample carrier 10A further
includes a sample tube blocking member 70 having a laterally
extending blocking wall 71 and a upper support wall 72 depending
therefrom which is in touching contact with a top surface 21 of the
transverse wall 20. The lower support wall 40 may be an integral
component or it may comprise, for example, an upper portion 40A and
a lower portion 40B, as shown in FIG. 1. In a preferred embodiment,
the transverse wall 20 and the upper portion 40A of the lower
support wall 40 form one integral component and the base 30 and the
lower portion 40B of the lower support wall form another integral
component, the two components being joined together by such means
as a snap-fit, ultrasonic welding, adhesive, screws, clips or other
mechanical fasteners.
Spaced-apart openings 22 are included in the transverse wall 20
(see FIGS. 1 and 8) which may be of the same or different sizes and
are dimensioned to receive sample tubes 300 into the sample carrier
10A. Each opening 22 is positioned above a sample tube receiving
area 60, as described below. As illustrated in FIGS. 1 and 8, the
transverse wall 20 includes a chamfered ring 23 circumscribing each
opening 22 to facilitate insertion of the sample tubes 300 into the
sample carrier 10A. An inner surface 24 of each opening 22 is
preferably sized to receive the cap component 310 of the sample
tube 300 in touching contact, which may be a frictional fit,
preferably allowing the longitudinal axis of the cap component to
move laterally from the longitudinal axis of the opening no more
than about 0.125 inches (3.12 mm), and more preferably no more than
about 0.1 inches (2.54 mm). Accordingly, in a preferred application
the sample carrier 10A is dimensioned so that at least a portion of
each cap 310 is contained within an opening 22 between top and
bottom surfaces 21, 25 of the transverse wall 20 when the sample
tubes 310 are fully inserted into the sample tube receiving areas
60. Restricting lateral movement of sample tubes held by the sample
carrier 10A is particularly important when the sample tubes include
penetrable caps, such as those disclosed by Anderson et al., U.S.
Patent Application No. 20010041336 A1, and Kacian et al., U.S.
Patent Application No. 20020127147 A1, because the caps may have
structurally weakened centers or contain filters with centrally
located passages or slits which must be penetrated by a pipette tip
or other fluid transfer device associated with an automated
sampling device.
The figures show a preferred embodiment in which the transverse
wall 20 extends laterally in both directions relative to the lower
support wall 40 and includes a series of openings 22 aligned along
each side of the lower support wall. The number of openings 22 on
each side of the lower support wall 40 is preferably 10. The
present invention also contemplates sample carriers (not shown)
which include a single series of openings 22 in the transverse wall
20, where the top wall extends laterally in only one direction
relative to the lower support wall 40.
FIG. 2 shows an alternative and less preferred sample carrier 10B
in which the transverse transverse wall 20 is eliminated and the
upper portion 40A of the lower support wall 40 and the sample tube
blocking member 70 are joined directly. In this embodiment, the
upper portion 40A of the lower support wall 40 extends higher than
it does in the preferred sample carrier 10A to account for the lost
thickness of the transverse wall 20. This sample carrier 10B is
less preferred because it is more difficult to control lateral
movement of the capped ends of the sample tubes 300.
As illustrated in the figures, the preferred sample carrier 10A
includes a plurality of sample tube receiving areas 60A for
receiving and positioning sample tubes 300 in substantially
vertical orientations on the sample carrier (see, e.g., FIG. 6). In
the preferred embodiment shown in FIG. 7, the sample tube receiving
areas 60A include pairs of opposed retaining walls 61 extending
upward from the base 30 and having angled orientations relative to
the lower support wall 40. Each retaining wall 61 extends from a
partition 62 separating two sample tube receiving areas 60A or an
end wall 63, where the partition or end wall extends upward from
the base and radially or perpendicularly outward from the lower
portion 40B of the lower support wall 40. As depicted in FIGS. 1
and 7, each partition 62 and a pair of extending retaining walls 61
preferably form a solid Y-shaped divider 64. The inner angle of the
"V" portion of the Y-shaped dividers 64 is preferably about
124.degree. for those dividers on the outer radius and preferably
about 116.degree. for those dividers on the inner radius of the
preferred arcuately shaped sample carrier 10A illustrated in FIGS.
1 and 7.
An opening 31 positioned in the base 30 of each sample tube
receiving area 60A permits corrosive agents, such as bleach, to be
drained from the sample carrier 10A. The use of these openings 31
also favorably minimizes the amount of material needed to form the
sample carrier 10A.
A spring 50 is disposed within each sample tube receiving area 60A
of the sample carrier 10A. The preferred springs 50 are leaf
springs made of stainless steel which extend outward from the lower
portion 40B of the lower support wall 40 (see FIGS. 3, 6 and 7)
through slots 41 formed therein and function to bias the sample
tubes 300 against retaining walls 61 of sample tube receiving areas
60A. The preferred springs 50 form part of a pair of spring cages
51 comprising a plurality of springs (preferably 10), as shown in
FIGS. 4 and 5. Each spring 50 of each spring cage 51 includes a
vertical post 52 and a spring arm 53 extending downwardly and
outwardly therefrom. The springs 50 are designed to provide a
sufficient degree of tension to their respective sample tubes 300
to hold the sample tubes in an immobilized state as aliquots of
sample are being removed from the sample tubes. The ends 54 of the
spring arms 53 are rounded to facilitate insertion and removal of
sample tubes 300 into corresponding sample tube receiving areas
60A.
The holding force of each spring 50 is preferably at least about
0.5 pounds force (2.22 N). This force value was selected to be
sufficient to maintain sample tubes 300 held by the sample carrier
10A in a substantially vertical orientation and to limit rotation
of the sample tubes during use so that labels 90 applied to the
sample tubes can be positioned for viewing within the sample
carrier, as shown in FIG. 6. To increase the coefficient of
friction between the springs 50 and outer surfaces 321 of the
vessel components 320 of the sample tubes 300, the spring arms 53
may be physically or chemically altered, such as by sand-blasting
or etching the surface of the spring arms using techniques well
known in the art. The coefficient of friction should not be so
great that the sample tubes 300 cannot be manually removed from the
sample tube receiving areas 60A without difficulty. FIG. 11
provides a section side view of the preferred sample carrier 10A
showing two sample tubes 300 which have been secured in the sample
tube receiving areas 60A by the leaf springs 50.
The spring cages 51 include a base 55 for joining the vertical
posts 52 to each other, as illustrated in FIGS. 4 and 5. Extending
from each base 55 are a series of outwardly extending tabs 56
interspersed between the vertical posts 52, as illustrated in FIGS.
4 and 5. FIG. 12 shows that each tab 56 extends outwardly a
sufficient distance to be in an interference fit with an inner
surface 65 of one of the partitions 62 of the sample tube receiving
area 60A when U-shaped elbows 57 of the spring cages 51 are
inserted into recesses 42 formed in the lower portion 40B of the
lower support wall 40, where pairs of opposed recesses are
separated by a series of longitudinally or arcuately oriented
dividing walls 43 (see FIG. 11). The spring cages 51 are moved into
position from the base 40 of the sample carrier 10A by sliding a
pair of end tabs 58 on each spring cage between opposed, parallel
guide rails 66A, 66B which extend vertically and outwardly from
each end wall 63, as depicted in FIGS. 12 and 13. Bottom surfaces
44 of the lower portion 40B of the lower support wall 40 make
contact with and arrest movement of the base 55 when the spring
cage 51 is in position. Inner walls 45 of the lower portion 40B of
the lower support wall 40 keep the spring cages 51 spaced-apart and
force the tabs 56 against the inner surfaces 65 of the partitions
62, thereby creating an interference fit which locks the spring
cages into position within the sample carrier 10A.
In an alternative sample carrier 10C according to the present
invention, a plurality of finger springs 150 substitute for each
leaf spring 60 of the preferred sample carrier 10A, as shown in
FIG. 15. In this embodiment, sets of equally-spaced finger springs
150 are arrayed about the periphery of openings 80 formed in a
laterally extending wall 81 and depend from a bottom surface 82
thereof. The lateral wall 81 can bisect the lower support wall 40
into upper and lower portions 40A,B, as illustrated in FIG. 15. Any
appropriate attachment means (e.g., screws 47) may be used to join
together the lateral wall 81 and the upper and lower portions 40A,B
of the lower support wall 40, however, it is preferred that aligned
holes 83, 46 be provided in the lateral wall and a top wall 48 of
the lower portion of the lower support wall for receiving screws
therethrough which can be threadingly inserted into mated threads
(not shown) provided in the upper portion of the lower support
wall.
Each opening 80 in the laterally extending wall 81 is located above
a sample tube receiving area 60B and is sized to receive the vessel
component 320 of a sample tube 300 therethrough. Sets of finger
springs 150 are preferably made up of four finger springs, as shown
in FIG. 18, where each finger spring includes an inwardly sloping
arm 151 and a distal node 152 having a curved end-surface 153 to
facilitate removal of sample tubes 300 from the sample carrier 10C.
The arrangement of each set of finger springs 150 about the
periphery of an opening 80 should be such that the vessel component
320 of a sample tube 300 will be substantially centered within the
corresponding opening 80 when the sample tube is inserted into the
sample tube receiving area 60B. See FIG. 16. And, like the holding
force of each leaf spring 50 in the preferred sample carrier 10A,
the collective holding force of each set of finger springs 150 is
preferably at least about 1.0 pound force (4.45 N), and more
preferably at least about 1.5 pounds force (6.67 N). Also, to
maintain sample tubes 300 held by the sample carrier 10C in a
substantially vertical orientation during use, as illustrated in
the side-section view of the sample carrier in FIG. 17, the
openings 22 in the transverse wall 20 and the corresponding
openings 80 in the lateral wall 81 are substantially co-axial.
While it is not necessary for holding and properly orienting sample
tubes 300 in the sample carrier 10C, partitions, such as the
T-shaped dividers 67 shown in FIG. 15, may be included for
separating the sample tube receiving areas of the sample carrier
10C. When included, these dividers 67 preferably extend outward
from the lower portion 40B of the lower support wall 40 and upward
from the base 30 to the bottom surface 82 of the lateral wall 81,
providing the lateral wall and the sample carrier 10C with
additional rigidity.
FIGS. 19 and 20 illustrate another sample carrier 10D according to
the present invention, in which no springs are included for holding
the sample tubes 300. Instead, a base 130 of the sample carrier 10D
has slots 60C formed therein for receiving the sample tubes 300,
where the slots constitute sample tube receiving areas. The slots
60C are preferably dimensioned to hold the sample tubes 300 in
substantially vertical orientations. Vertical slits 68 extending
through an outer surface 131 of the base 130 may be provided to
permit viewing of machine readable labels 90 (e.g., scannable bar
codes) present on sample tubes 300 held in the slots 60C. The
labels 90 may provide information about, for example, the contents
of the sample tubes 300 or assays to be performed on such
contents.
In each of the sample carriers 10 illustrated in the figures, the
sample tube blocking member 70 is provided to prevent sample tubes
300 from being removed from their corresponding sample tube
receiving areas 60 during automated sampling. This feature is
particularly important when the sample tubes 300 include caps 310
requiring penetration by a sampling device (e.g., robotic pipettor)
since the friction between penetrated caps and sampling devices may
overcome the holding forces of the sample tube receiving areas 60,
resulting in partial or complete removal of sample tubes from the
sample carriers 10 during sampling. Thus, the sample tube blocking
member 70 serves as a fail-safe in the event that sample tube
receiving areas 60 fail to maintain sample tubes 300 in the sample
carriers 10 during sampling.
As shown in FIG. 9, the blocking wall 71 includes at least one
lateral edge 73 extending over at least a portion of the top rim
322 of the cap component 310 of one or more sample tubes 300 held
by the sample carrier 10. A label 95 bearing alpha-numerical
information may be applied to a top surface 79 of the blocking wall
71 to aid in identifying the locations of adjacent sample tubes
300, as depicted in FIG. 9. The illustrated caps 310 include
penetrable seals 323 applied to the top rims for maintaining
aerosol filters (not shown) within the caps. In the preferred
embodiment, the blocking wall 71 includes two lateral edges 73,
each lateral edge extending over a set of aligned sample tubes 300
on each side of the lower support wall 40 of the sample carrier 10.
The distance that the lateral edges 73 extend over the sample tubes
300 is limited to permit non-interfering access to the contents of
the sample tubes by a fluid transfer device (e.g., pipette tip)
associated with an automated sampling device, such as a robotic
pipettor.
A bottom surface 74 of the blocking wall 71 is preferably no more
than about 0.1 inches (2.54 mm) above the top rim 322 of the cap
component 310 of each sample tube 300 held by the sample carrier
10. Alternatively, the distance between the bottom surface 74 of
the blocking wall 71 and the top rim 322 of the cap component 310
of each sample tube 300 is set so that the sample tubes cannot be
fully withdrawn from the sample tube receiving areas 60 before
their vertical movement is impeded by the blocking wall. While the
upper support wall 72 depending from the blocking wall 71 serves to
elevate the blocking wall above the transverse wall 20 of the
sample carrier 10A,C embodiments shown in FIGS. 1 and 15, this
feature would not be required in the sample carrier 10B,D
embodiments shown in FIGS. 2 and 20, provided the height of the
lower support wall 40 is adjusted to accommodate sample tubes 300
below the bottom surface 74 of the blocking wall 71.
FIGS. 1 3 and 15 illustrate preferred means for joining the sample
tube blocking member 70 to the transverse wall 20 or the lower
support wall 40. In these embodiments, a pair of metal pins 100 are
fixed to the transverse wall 20 or the lower support wall 40 and
extend upward from top surfaces 21, 49 thereof. These pins 100 are
aligned with a pair of through-holes 75 which extend through the
sample tube blocking member 70, as shown in FIG. 10. To aid in
joining the sample tube blocking member 70 to the transverse wall
20 or the lower support wall 40, FIG. 10 also shows that a bottom
surface 76 of the upper support wall 72 can be outfitted with a
pair of channels 77 adjoining and arranged on the same side of the
through-holes 75. Because the sample carriers 10 are preferably
used in conjunction with drip shields 200, as described infra, it
is not necessary to fixedly join the sample tube blocking member 70
to the transverse wall 20 or the lower support wall 40 prior to
use. However, in applications where a drip shield of the type
described below will not be used, it will be necessary to attach
the sample tube blocking member 70 to the traverse wall 20 or the
lower support wall 40 using mechanical fasteners (e.g., screws) if
the sample tube blocking member is to achieve its sample tube
containment function.
FIG. 14 shows an identification plate 110 attached to the sample
tube blocking member 70 which includes a label 120 providing
machine readable (i.e., bar code) and/or alpha-numerical
information. This information may inform an instrument or user of,
for example, the presence or location of a particular sample
carrier 10 in the instrument, the source of samples being carried
by the sample carrier and/or the types of assays to be performed on
the samples. The plate 110 may be fixed to the upper support wall
72 of the sample tube blocking member 70 by means of screws 111
threadingly inserted into mated screw holes 78 shown in FIG. 1.
For automated applications, it may be desirable to include means
for determining whether a sample tube 300 is present in or absent
from a particular sample tube receiving area 60 prior to pipetting.
This can be achieved in the present invention by providing a
machine readable label 140 to the lower support wall 40 above each
sample tube receiving area 60, as indicated in FIGS. 6 and 20. If
the sample tube 300 inserted into a sample tube receiving area 60
is sufficiently translucent, a machine for reading the labels 140,
such as a bar code scanner, will be unable to read or detect the
label behind the sample tube 300. Based its failure to read or
detect a label 140, the machine can communicate to a computer
controlling the operation of an associated automated sampling
system, (see, e.g., FIG. 21), that a sample tube 300 is present in
that particular sample tube receiving area 60. As a result, a
robotic pipettor (not shown) associated with the automated sampling
system will be instructed draw a predetermined amount of sample
from the sample tube 300 at that location. But, if a sample tube
300 is absent from a sample tube receiving area 60, a reading
machine associated with the automated sampling system will be able
to read or detect the corresponding label 140 and will communicate
to the computer that a sample tube 300 is not present in that
sample tube receiving area. Accordingly, no instruction will be
given to the robotic pipettor to draw sample from the sample tube
300 at that location.
The base 30, 130 of the sample carrier 10 may be adapted for use
with a sample carrier conveying means, such as a sample carousel
for rotating a plurality of sample carriers within an automated
sampling system. One such sample carousel 400 is disclosed by
Ammann et al. in U.S. Pat. No. 6,335,166 and is illustrated in FIG.
21. This particular sample carousel 400 is formed of milled,
unhardened aluminum and includes an annular trough 401 about the
periphery of a ring 402 and a plurality of raised, radially
extending dividers 403. The dividers 403 divide the trough 401 into
nine arcuate sample carrier receiving wells 404 which can be
configured to accommodate the sample carriers 10 of the present
invention. The individual sample carrier receiving wells 404 are
dimensioned to maintain the sample carriers 10 in an upright
position as sample tubes 300 held by the sample carriers 10 are
indexed under a robotic pipettor (not shown) for retrieving sample
material for analysis. To track individual sample carriers 10 on
the sample carousel 400, a machine readable label 120 (e.g.,
scannable bar code), can be provided to at least one end wall 63 or
to a plate 110 attached to the sample tube blocking member 70, as
described above and shown in FIG. 14.
The sample carriers 10 of the present invention can be used in
combination with a device for protecting sample tubes 300 during
sampling to further limit opportunities for cross-contamination.
Such a device is provided by a novel drip shield 200 depicted in
FIGS. 21 26. This drip shield 200 includes a cover plate 201 which
is dimensioned to form a canopy over a sample carrier 10 fully
contained thereunder. Thus, in a preferred embodiment, the drip
shield 200 has an arcuate shape corresponding to the preferred
arcuate shape of the sample carrier 10, as shown in FIG. 21. A
minimum of two through-holes, identified in FIGS. 21 23 as a first
through-hole 202 and a second through-hole 203, extend through the
drip shield 200 and provide access to sample tubes 300 centered
below the through-holes. The through-holes 202, 203 are dimensioned
to permit non-interfering passage therethrough by pipette tips
carried by a robotic pipettor, but are small enough so that a top
surface 204 of the drip shield 200 can function to catch hanging
droplets which are dislodged from the pipette tips during sample
transfer procedures. Therefore, the diameters of the first and
second through-holes 202, 203, respectively, are preferably about
the same as or less than the smallest diameter of any cap 310 of a
sample tube 300 to be carried by a sample carrier 10. Raised
annular rims 205, 206 can be provided about the periphery of the
first and second through-holes 202, 203, respectively, to impede
fluid collected on the top surface 204 of the cover plate 201 from
spilling into any of the sample tubes 300, as shown in FIGS. 22 and
24. In a preferred embodiment illustrated in FIG. 25, however, the
top surface 204 of the cover plate 201 includes a chamfered ring
207 about the periphery of the first and second through-holes 202,
203, respectively, to aid in redirecting misaligned pipette
tips.
The through-holes 202, 203 are arranged on the drip shield 200 so
that the first through-hole 202 is positioned above a first or
inner row of longitudinally or arcuately aligned sample tubes 300
and the second through-hole 203 is aligned above a second or outer
row of longitudinally or arcuately aligned sample tubes. As the
sample carrier 10 is indexed forward under the drip shield 200 by
the sample carousel 400, the next sample tube 300 in each row of
tubes can be presented under one of the through-holes 202, 203 for
access by a robotic pipettor. An example of a robotic pipettor for
use with the present invention is the Robotic Sample Processor,
Model No. RSP9000, available from Cavro, Inc. of Sunnyvale, Calif.
The through-holes 202, 203 are preferably offset on the drip shield
200 to further minimize opportunities for contamination resulting
from released hanging droplets of sample. In a preferred mode, the
through-holes 202, 203 are arranged on the drip shield 200, as
shown in FIG. 21, so that the third sample tube 200 in the second
or outer row of aligned tubes is being sampled as the first sample
tube in the first or inner row of aligned tubes is being
sampled.
When the drip shield 200 is employed in an automated sampling
system, the drip shield preferably includes a series of three
longitudinally or arcuately extending runners 208 which are spaced
apart from each other and depend from a bottom surface 209 of the
drip shield, as illustrated in FIG. 23. (The reference number "208"
refers generally to all three runners shown in the figures, whereas
the reference number "208A" refers to the inner runner and the
reference number "208B" refers to the two outer runners.) The inner
runner 208A is constructed and arranged on the bottom surface 209
of the drip shield 200 to limit vertical movement of the sample
carrier 10 under the drip shield, as illustrated in FIG. 26.
Vertical movement of the sample carrier 10 is of particular concern
when a robotic pipettor is used to withdraw test sample from sample
tubes 300 having penetrable caps 310. Depending on the withdrawal
force required, it may be possible for a pipette tip mounted on a
robotic pipettor to become snagged on the penetrable components of
the cap 310 as the pipette tip is being withdrawn from the sample
tube 300. As a consequence, a portion of the sample carrier 10 may
be lifted from, and possibly relocated on, the sample carrousel 400
by the robotic pipettor. Therefore, to limit vertical movement of
the sample carrier 10 under the drip shield 200, the distance
between a bottom surface 210 of the inner runner 208A and a top
surface 79 of the blocking wall 71 of the sample tube blocking
member 70 is less than the vertical distance needed to extract or
displace at least a portion of the sample carrier from its location
on the sample carousel 400 (e.g., less than the depth of the sample
carousel receiving well 404). Vertical relocation of a sample
carrier 10 may occur when the retention force of a sample tube 300
(i.e., the cap component 310) applied to a pipette tip being
withdrawn from the sample tube exceeds the holding force of a
spring 50 or springs 150 applied to the sample tube. Preferably,
the distance between the bottom surface 210 of the inner runner
208A and the top surface 79 of the blocking wall 71 of the sample
tube blocking member 70 is no more than about 0.125 inches (3.18
mm). The inner runner 208A can also function as a barrier to
carryover contamination between sample tubes 300 held in sample
tube receiving areas 60 on opposite sides of the lower support wall
40 of the sample carrier 10.
The preferred runners 208A, 208B have tapered ends 211, 212,
respectively, as shown in FIG. 23. The tapered ends 211 of the
inner runner 208A are provided to facilitate proper seating of
sample carriers 10 which have not been fully inserted into sample
carousel receiving wells 404 prior to rotation, whether the sample
carousel 400 is being rotated clockwise or counterclockwise. The
outer runners 208B are spaced-apart from the inner runner 208A such
that inner side walls 213 of the outer runners 208B and both side
walls 214 of the inner runner 208B are positioned vertically above
and overhang sample tubes 300 which are held by the sample carrier
10 and positioned beneath the drip shield 200, as shown in FIG. 26.
Opposed side walls 213, 214 of the runners 208A, 208B preferably do
not extend beyond the periphery of the through-holes 202, 203 of
the drip shield 200, thereby permitting non-interfering passage of
fluid transverse devices through the through-holes 213, 214. In
this way, the runners 208 function as an additional failsafe for
blocking vertical movement of sample tubes 300 held by the sample
carrier 10 in the event that a sample tube is unexpectedly
extracted beyond the sample tube blocking member 70 during
pipetting.
The drip shield 200 can be maintained in fixed relationship over
sample carriers 10 being indexed on the sample carousel 400
therebelow by means of mounting posts 215 fixed to a stationary
surface 216 of the automated sampling system, as illustrated in
FIG. 21 and more fully described by Ammann et al. in U.S. Pat. No.
6,335,166. The drip shield 200 can be secured to these mounting
posts 215 using screws, bolts or like mechanical fasteners.
Preferred are bolts 217 mated with threaded holes (not shown) in
the mounting posts 215 and inserted through three through-holes 218
located on the periphery of the drip shield 200, as shown in FIG.
21.
Sample carriers 10 and drip shields 200 of the present invention
are preferably made of a substantially non-conductive plastic, such
as acrylonitrile-butadiene-styrene (ABS), which can be obtained
from GE Plastics of Pittsfield, Mass. as Cycolac.RTM. MG47. The
materials used should be selected to resist corrosion by chemicals
and reagents that the sample carrier 10 and drip shield 200 may be
exposed to during use. The drip shield 200 and the sample tube
blocking member 70, the transverse wall 20 and the upper portion
40A of the lower support wall 40 of the preferred sample carrier
10A are preferably machined components. The remainder of the
components of the preferred sample carrier 10A are preferably
formed by injection molding procedures known to those skilled in
the art.
While the present invention has been described and shown in
considerable detail with reference to certain preferred
embodiments, those skilled in the art will readily appreciate other
embodiments of the present invention. Accordingly, the present
invention is deemed to include all modifications and variations
encompassed within the spirit and scope of the following appended
claims.
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